Since components of an electronic device usually wear out during the operation of the electronic device, and the square of power is directly proportional to the square of the current, therefore the greater the current, the larger is the damage or consumption of the components. Furthermore, the power required for a vast majority of components of the present computers becomes increasingly larger, and thus the damage and consumption are increased accordingly. Such damage and consumption represent the production of waste heat, and an increase of consumption and damage indicates that more waste heats are produced by the components in the electronic device, and the internal temperature of the electronic device will rise unceasingly. If such heat is not dissipated timely, then an overheating may affect normal operations of the electronic components. Inventions for enhancing or extending the working efficiency of a heat dissipating fan were disclosed in R.O.C. Patent Publication No. 392106 entitled “Heat dissipating fan delay switch for computer motherboard” for the situation of unable to reduce the accumulated heat or lower the temperature after the computer system is turned off. Such patented invention provides the technology of outputting a fan ON/OFF control signal from a South Bridge chip and sending the control signal from a control circuit to a fan power supply switching ON/OFF circuit to convert the power supply when the heat dissipating fan is off, so as to delay the time of shutting down the fan after the computer is turned off, and increase the heat dissipating time; and R.O.C. Patent Publication No. 400968 entitled “Delay ON/OFF apparatus of a heat dissipating fan” for providing the technology of electrically connecting a stationary power system and a primary power supply system to supply electric power with a delay ON/OFF apparatus, and switch and supply different electric power to drive the heat dissipating fan when the computer system is on or off, but the technology disclosed in R.O.C. Patent Publication No. 400968 is used extensively in the present market. Technologies based on such technology were developed and disclosed in R.O.C. Patent Publication No. 572579 entitled “Power supply with a heat dissipating effect after a computer is turned off”, R.O.C, Patent Publication No. 568300 entitled “Control apparatus for fan operating mode”, R.O.C, Patent No. M247876 entitled “Temperature recovery preventing apparatus driven by a power supply enabling system for compulsorily dissipating heat when a computer is turned off” and R.O.C. Pat. No. M268654 entitled “Delay apparatus for heat dissipating fan independent to power supply”. The main innovative ideas of the aforementioned patents reside on that after a computer is turned off, the operation of the heat dissipating fan is delayed, so that the fan can be operated continuously for a period of time after the computer is shut down. However, the power output of the present power supply is increased significantly up to thousands of watts, and thus the stationary power for maintaining the operation of the computer anytime also will produce a significant amount of waste heat, and the prior art is limited to the extension of the working time of the heat dissipating fan after the computer is turned off, but it cannot start the heat dissipating fan while the computer is off. As a result, the internal temperature of a shut-down computer still rises constantly. Obviously, we need a feasible solution for providing the heat dissipating capability for a computer, when the computer is turned off at regular time.